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TomT
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Since I was stuck in this very slow moving traffic for more than an hour, I had a chance to play with different modes and see what affect, if any, they had. The bottom line was that the escalating "grabby" brake issue was the same in both D and Eco. And at the much slower than walking pace speeds I was going, you basically can get almost no regeneration so it was pretty much all friction brakes... Either using the parking brake or placing the car in park/neutral so you can remove your foot completely from the brake pedal on occasion seems to be the only solution to clearing the problem in such a situation. In my opinion, it definitely is an issue they need to address - and could actually be a safety consideration - and I suspect it has to do with the Brake Assist function logic.
LEAFfan wrote:
GroundLoop wrote:I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)
Is there a reason why you didn't use ECO so you wouldn't have to use your brakes so much? Even going down the mountains, I always use ECO and rarely need to use my brakes.
Last edited by TomT on Sun Oct 30, 2011 10:31 am, edited 2 times in total.
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Jim66
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Location: Carlsbad, CA

Re: Brakes "mutate" to become grabby in stop & go traffic?

I've experienced the same thing while creeping in traffic, also in Eco mode. Happened during the gridlock of the San Diego power outage. Thanks for the tips about using Park or removing my foot from the brake completely.
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GroundLoop
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Re: Brakes "mutate" to become grabby in stop & go traffic?

This is very interesting, as I have never seen a car behave this way. It's very repeatable, and the other threads are describing the same thing.

I'm also coming around to thinking there might be an actual safety risk here. If stop & go traffic progresses up in speed to where you're allowing a full downhill roll, the mildest application of brakes could get you rear-ended.

I don't think it has much (if anything) to do with regen, since regen wouldn't be used at these low speeds and, after all, it works just fine for a while. The friction brakes shouldn't be this touchy.
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gbarry42
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Presumably, when you reach a "full downhill roll", your foot is off the brake, and the system has reset. BTW, I've noticed this brake behavior, too, and remember reading about it previously.
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JustinC
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Re: Brakes "mutate" to become grabby in stop & go traffic?

Has anyone actually talked to the mechanics at the dealer about this? It's frustrating to see people pointing out other threads on the same issue as if it's just some newbie issue. Those threads don't have any resolution and are a waste of time to read. This is a real problem and needs to be addressed by Nissan.

I'm happy to be the one who actually goes to the service department with this, I'm just wondering if anyone has tried that yet.
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aqn
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Re: Brakes "mutate" to become grabby in stop & go traffic?

GroundLoop wrote:I was stuck in slow-moving traffic going downhill, gradually releasing and applying the brakes to creep along, one car length at a time. (No accelerator at all.)

Over about 10 minutes, the brakes took on a very "binary" feel -- they were either grabbing hard, or fully released, and I couldn't gently apply them. They became very "grippy" and abrupt. I tried releasing completely, but didn't get any improvement.
I have experienced this behavior, but have not reported it because I have not spent the time to see if it's reproducible. I think my circumstance was similar to yours: stop-and-go traffic requiring irregular use of the brakes.
JustinC wrote:Has anyone actually talked to the mechanics at the dealer about this? [...] I'm happy to be the one who actually goes to the service department with this, I'm just wondering if anyone has tried that yet.
I don't like going to the dealer with a problem that is not readily reproducible. It'd be a waste of my time and probably theirs too. The best I can hope for is a recorded diagnostic trouble code (DTC) that may or may not provide a clue, though I imagine if it's worthwhile for the car to record a DTC, it would have shown me a warning light or two as well.
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EVDRIVER
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Re: Brakes "mutate" to become grabby in stop & go traffic?

You are correct about the warning light, without one there is likely nothing recorded since those codes would generate some type of alert if recurring.
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johnr
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Re: Brakes "mutate" to become grabby in stop & go traffic?

The best thing to do is, if you can reproduce the issue, schedule a service appointment and bring the car to the dealer to demonstrate to them. They can enter it into their system and Nissan would work toward a resolution. I am going to do this, but first I'm reading other peoples' experiences here to figure out how to consistently reproduce the problem for the dealer.
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GeekEV
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Re: Brakes "mutate" to become grabby in stop & go traffic?

And therein lies the challenge...

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GroundLoop
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Re: Brakes "mutate" to become grabby in stop & go traffic?

It's not a challenge at all -- I can reproduce it 100% in a 5-minute test drive.
All it takes is a downhill grade and some patience. Stop, creep forward, stop, creep forward..
keep it up for a short while and the brakes freak out.

I'd prefer to do this in the dealer's own demo car, so mine doesn't end up in their service bay for two weeks. :)

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